US6654162B2ExpiredUtilityPatentIndex 82
Raman amplifier, optical repeater, and Raman amplification method
Est. expiryJul 23, 2018(expired)· nominal 20-yr term from priority
H01S 3/13013H01S 3/2375H01S 3/094011H01S 3/10015H01S 3/094015H01S 3/06754H01S 3/2383H01S 3/094096H01S 3/06758H01S 3/302H04B 10/2916H01S 2301/04H01S 3/0912
82
PatentIndex Score
10
Cited by
79
References
122
Claims
Abstract
A Raman amplifier according to the present invention comprises a plurality of pumping means using semiconductor lasers of Fabry-Perot, DFB, or DBR type or MOPAs, and pumping lights outputted from the pumping means have different central wavelengths, and interval between the adjacent central wavelength is greater than 6 nm and smaller than 35 nm. An optical repeater according to the present invention comprises the above-mentioned Raman amplifier and adapted to compensate loss in an optical fiber transmission line by the Raman amplifier. In a Raman amplification method according to the present invention, the shorter the central wavelength of the pumping light the higher light power of said pumping light. In the Raman amplifier according to the present invention, when a certain pumping wavelength is defined as a first channel, and second to n-th channels are defined to be arranged with an interval of about 1 THz toward a longer wavelength side, the pumping lights having wavelengths corresponding to the first to n-th channels are multiplexed, and an pumping light having a wavelength spaced apart from the n-th channel by 2 THz or more toward the longer wavelength side is combined with the multiplexed light, thereby forming the pumping light source. The pumping lights having wavelengths corresponding to the channels other than (n-1)-th and (n-2)-th channels may be multiplexed, thereby forming the pumping light source. The pumping lights having wavelengths corresponding to the channels other than (n-2)-th and (n-3)-th channels may be multiplexed, thereby forming the pumping light source.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1. A multispectral light source for a Raman amplifier, comprising:
a pump configured to provide pump light to an optical fiber while a wavelength division multiplex, WDM, optical signal, with a signal bandwidth of at least 20 nm, propagates though the optical fiber,
the pump includes
a first light source configured to produce light so as to create a corresponding first gain profile having a peak gain at a first wavelength, and
a second light source configured to produce light so as to create a corresponding second gain profile having a peak gain at a second wavelength, wherein
a composite gain profile created from a combination of the first gain profile and the second gain profile has an amplification bandwidth that is at least as great as the 20 nm signal bandwidth and overlaps said signal bandwidth so as to provide Raman gain to said WDM optical signal,
said second wavelength being at a longer wavelength than the first wavelength, and
said optical fiber to which said pump light is provided is not an Erbium doped fiber of an EDFA.
2. The multispectral light source of claim 1 , wherein:
the peak gain of the second gain profile being greater than the peak gain of the first gain profile.
3. The multispectral light source of claim 1 , wherein:
the first light source includes at least one laser configured to produce light at a first pump light wavelength; and
the second light source includes a second laser configured to produce light at a second pump light wavelength.
4. The multispectral light source of claim 1 , wherein:
a power output of light from said first light source prior to being coupled into the optical fiber being set to a different level than light from the second light source so as to flatten the composite gain profile.
5. The multispectral light source of claim 3 , wherein:
said first light source includes at least three lasers configured to respectively produce light at the first pump light wavelength, a third pump light wavelength and a fourth pump light wavelength, which are multiplexed together so as to produce a combined gain profile that has less unevenness than if the first gain profile was produced from pump light having only one wavelength.
6. The multispectral light source of claim 5 wherein:
a largest interval between adjacent wavelengths of the first, third and fourth pump light wavelengths being less than a closest wavelength between the second pump light wavelength and any of the first, third and fourth pump light wavelengths.
7. The multispectral light source of claim 3 , wherein:
the at least one laser being a semiconductor laser.
8. The multispectral light source of claim 7 , wherein:
said semiconductor laser being a Fabry-Perot laser.
9. The multispectral light source of claim 8 , further comprising:
an external resonator coupled to an output of the Fabry-Perot laser.
10. The multispectral light source of claim 7 , wherein:
said semiconductor laser being at least one of a DFB laser, a DBR laser and a MOPA.
11. The multispectral light source of claim 5 , wherein:
a total gain of said combined first gain profile being greater than that of the second gain profile.
12. The multispectral light source of claim 5 , wherein:
a total pump power of all lasers producing pump light at shorter wavelengths than the second wavelength being greater than a pump power of the second laser.
13. The multispectral light source of claim 1 , further comprising:
means for suppressing an unevenness in the composite gain profile.
14. The multispectral light source of claim 13 , wherein:
said means for suppressing includes combining the first gain profile with other gain profiles produced from another source of light.
15. The multispectral light source of claim 14 , wherein:
said means for suppressing includes means for adjusting a power output of at least one of said first light source, said second light source, and said another source of light.
16. The multispectral light source of claim 14 , wherein:
said means for suppressing includes setting the other gain profiles to have a longest wavelength that is closer to one of the wavelengths of the other gain profiles than the second wavelength.
17. The multispectral light source of claim 1 , further comprising:
means for compensating for optical fiber loss wavelength dependency of the lights from the first light source and the second light source.
18. The multispectral light source of claim 1 , further comprising:
means for compensating for Raman effect between lights from the first light source and the second light source.
19. A multispectral light source for a Raman amplifier, comprising:
means for providing pump light to an optical fiber while a wavelength division multiplex, WDM, optical signal, with a signal bandwidth of at least 20 nm, propagates though the optical fiber; and
means for coupling the pump light into the optical fiber, wherein
the means for providing light includes
a first light source configured to produce light so as to create a corresponding first gain profile having a peak gain at a first wavelength, and
a second light source configured to produce light so as to create a corresponding second gain profile having a peak gain at a second wavelength, wherein
a composite gain profile created from a combination of the first gain profile and the second gain profile has an amplification bandwidth that is at least as great as the 20 nm signal bandwidth and overlaps said signal bandwidth so as to provide Raman gain to said WDM optical signal,
said second wavelength being at a longer wavelength than the first wavelength, and
said optical fiber to which said pump light is provided is not an Erbium doped fiber of an EDFA.
20. The multispectral light source of claim 19 , wherein:
the peak gain of the second gain profile being greater than the peak gain of the first gain profile.
21. The multispectral light source of claim 19 , wherein:
the first light source includes a first laser that produces light at a predetermined wavelength, and
the second light source includes another laser that is configured to produce light at another predetermined wavelength.
22. The multispectral light source of claim 19 , wherein:
said means for providing light includes means for setting a power output of said first light source to a different level than that for the second light source so as to flatten the composite gain profile.
23. The multispectral light source of claim 21 , wherein said means for providing light includes:
means for supplementing the first gain profile with other gain profiles to provide a combined gain profile that has less unevenness than if produced from a light source having only one wavelength.
24. The multispectral light source of claim 19 , wherein:
said means for providing light includes means for stabilizing the light from the first light source and the light from the second light source.
25. The multispectral light source of claim 23 , wherein:
said means for supplementing provides said combined first gain profile with a greater total gain than that of the second gain profile.
26. The multispectral light source of claim 23 , wherein:
a total pump power of light from said first light source prior to being coupled into the optical fiber being set to a different level than light from the second light source.
27. The multispectral light source of claim 19 , further comprising:
means for suppressing an unevenness in the composite gain profile.
28. The multispectral light source of claim 27 , wherein:
said means for suppressing includes combining the first gain profile with other gain profiles produced from another source of light.
29. The multispectral light source of claim 28 , wherein:
said means for suppressing includes means for adjusting a power output of at least one of said first light source, said second light source, and said another source of light.
30. The multispectral light source of claim 28 , wherein:
said means for suppressing includes means for setting the other gain profiles to have a longest wavelength that is closer to one of the wavelengths of the other gain profiles than the second wavelength.
31. The multispectral light source of claim 19 , further comprising:
means for compensating for optical fiber loss wavelength dependency of the lights from the laser, the first light source, and the second light source.
32. The multispectral light source of claim 19 , further comprising:
means for compensating for Raman effect between lights from the first light source, and the second light source.
33. A method for supplying pump light for Raman amplifying a WDM signal, comprising steps of:
providing pump light to an optical fiber while a wavelength division multiplex, WDM, optical signal, with a signal bandwidth of at least 20 nm, propagates though the optical fiber, including
producing light from a first light source so as to create a corresponding first gain profile having a peak gain at a first wavelength, and
producing light from a second light source so as to create a corresponding second gain profile having a peak gain at a second wavelength, wherein
a composite gain profile created from a combination of the first gain profile and the second gain profile has an amplification bandwidth that is at least as great as the 20 nm signal bandwidth, and overlaps said signal bandwidth so as to provide Raman gain to said WDM optical signal,
said second wavelength being longer than the first wavelength, and
said optical fiber to which said pump light is provided is not an Erbium doped fiber of an EDFA.
34. The method of claim 33 , wherein:
the peak gain of the second gain profile being greater than the peak gain of the first gain profile.
35. The method of claim 33 , wherein:
the producing light from a first light source step comprises producing light from at least one laser at a single wavelength.
36. The method of claim 33 , wherein:
said step of producing light from a first light source includes setting a power output of said first light source to a different level than that for the second light source so as to flatten the composite gain profile.
37. The method of claim 35 , wherein:
said step of producing light from a first light source includes producing light at a first pump light wavelength, and further comprising steps of
producing light at third and fourth pump light wavelengths respectively; and
multiplexing the light at the first, third and fourth pump light so as to produce a combined gain profile that has less unevenness than if light having only one wavelength were used.
38. The method of claim 37 , wherein said step of producing light at third and fourth pump light wavelengths includes setting a largest interval between adjacent pump lights of the first, third and fourth pump light wavelengths to be less than a closest wavelength between the second pump light and any of the first, third and fourth pump lights.
39. The method of claim 37 , wherein:
a total gain of said combined gain profile being greater than that of the second gain profile.
40. The method of claim 37 , further comprising steps of:
setting a total pump power of all pump light having a shorter wavelength than the second pump light to be greater than a pump power of the second pump light.
41. The method of claim 33 , fiber comprising a step of:
suppressing an unevenness in the composite gain profile.
42. The method of claim 41 , wherein:
said suppressing step includes combining the first gain profile with other gain profiles.
43. The method of claim 42 , wherein:
said suppressing step includes adjusting a power output of at least one of said first pump light and said second pump light.
44. The method of claim 33 , further comprising a step of:
compensating for optical fiber loss wavelength dependency of pump lights having a wavelength less than the second pump light.
45. The method of claim 30 , further comprising a step of:
compensating for Raman effect between pump lights.
46. A multispectral light source for a Raman amplifier, comprising:
a pump configured to provide pump light to an optical fiber while a wavelength division multiplex, WDM, optical signal, with a signal bandwidth of at least 20 nm, propagates though the optical fiber, including
a first light source configured to produce light at a first predetermined power level at an output of the first light source so as to create a corresponding first gain profile in said optical fiber having a peak gain at a first wavelength, and
a second light source configured to produce light at a second predetermined power level at an output of said second light source so as to create a corresponding second gain profile in said optical fiber having a peak gain at a second wavelength, wherein
a composite gain profile created from a combination of the first gain profile and the second gain profile has an amplification bandwidth that is at least as great as the 20 nm signal bandwidth, and overlaps said signal bandwidth so as to provide Raman gain to said WDM optical signal,
said second wavelength being longer than the first wavelength, and
said optical fiber to which said pump light is provided is not an Erbium doped fiber of an EDFA.
47. The multispectral light source of claim 46 , wherein:
the second predetermined power level being greater than the first predetermined power level so as to flatten the composite gain profile.
48. The multispectral light source of claim 46 , wherein:
the first light source includes at least one laser configured to produce light at a first pump light wavelength; and
the second light source includes a laser configured to produce light at a second pump light wavelength.
49. The multispectral light source of claim 48 , wherein:
the first light source includes at least three lasers configured to produce light at the first pump light wavelength, a third pump light wavelength and a fourth pump light wavelength at first, third and fourth power levels respectively, that are multiplexed together so as to produce a combined gain profile that has less unevenness than if the first gain profile was produced from pump light having only one wavelength.
50. The multispectral light source of claim 49 , wherein:
a largest interval between adjacent wavelengths of the first, third and fourth pump light wavelengths being less than a closest wavelength between the second wavelength and any of the first, third and fourth pump light wavelengths.
51. The multispectral light source of claim 49 , wherein:
the at least three lasers each being a semiconductor laser.
52. The multispectral light source of claim 51 , wherein:
each semiconductor laser being a Fabry-Perot laser.
53. The multispectral light source of claim 51 , comprising:
an external resonator coupled to an output of the Fabry-Perot laser.
54. The multispectral light source of claim 51 , wherein:
said semiconductor laser being at least one of a DFB laser, a DBR laser and a MOPA.
55. The multispectral light source of claim 49 , wherein:
a total pump power of all lasers producing pump light at a shorter wavelength than the second wavelength being greater than a pump power of the second light source.
56. The multispectral light source of claim 46 , further comprising:
means for suppressing an unevenness in the composite gain profile.
57. The multispectral light source of claim 56 , wherein:
said means for suppressing includes combining the first gain profile with other gain profiles.
58. The multispectral light source of claim 57 , wherein:
said means for suppressing includes means for adjusting a power output of at least one of said first light source and said second light source.
59. The multispectral light source of claim 57 , wherein:
said means for suppressing includes setting the other gain profiles to be closer in wavelength to one another than to the second wavelength.
60. The multispectral light source of claim 46 , further comprising:
means for compensating for optical fiber loss wavelength dependency of the lights from the first light source and the second light source.
61. The multispectral light source of claim 46 , further comprising:
means for compensating for Raman effect between pump lights.
62. A method for supplying pump light for Raman amplifying a WDM signal, comprising steps of:
providing pump light to an optical fiber while a wavelength division multiplex, WDM, optical signal, with a signal bandwidth of at least 20 nm, propagates though the optical fiber, including
producing light from a first light source at a first predetermined power level so as to create a corresponding first gain profile having a peak gain at a first wavelength, and
producing light from a second light source at a second predetermined power level so as to create a corresponding second gain profile having a peak gain at a second wavelength, wherein
a composite gain profile created from a combination of the first gain profile and the second gain profile has an amplification bandwidth that is at least as great as the 20 nm signal bandwidth, and overlaps said signal bandwidth so as to provide Raman gain to said WDM optical signal,
said second wavelength being longer than the first wavelength, and
said optical fiber to which said pump light is provided is not an Erbium doped fiber of an EDFA.
63. The method of claim 61 , wherein:
the step of producing from a second light source includes setting the second predetermined power level so that the peak gain of the second gain profile is greater than the peak gain of the first gain profile.
64. The method of claim 61 , wherein:
the step of producing light from a first light source comprises producing from at least one laser at a single wavelength.
65. The method of claim 62 , wherein:
said step of producing light from a first light source includes setting a power output of said first light source to a different level than that for the second light source so as to flatten the composite gain profile.
66. The method of claim 64 , wherein:
said step of producing light from a first light source includes producing light at a first pump light wavelength and further comprising steps of
producing light at third and fourth pump light wavelengths and third and fourth power levels respectively; and
multiplexing the light at the first, third and fourth pump light wavelengths so as to produce a combined gain profile that has less unevenness than if light having only one wavelength were used.
67. The method of claim 66 , wherein said step of producing light at third and fourth pump light wavelengths includes setting a largest interval between adjacent pump lights of the first, third and fourth pump light wavelengths to be less than a closest wavelength between the second wavelength and any of the first, third and fourth pump lights.
68. The method of claim 66 , wherein:
a total power of all pump lights contributing to said combined gain profile being greater than that of all pump light contributing to the second gain profile.
69. The method of claim 66 , further comprising steps of:
setting a total pump power of all pump light having a shorter wavelength than the second wavelength to be greater than a pump power of the second pump light.
70. The method of claim 62 , further comprising a step of:
suppressing an unevenness in the composite gain profile.
71. The method of claim 70 , wherein:
said suppressing step includes combining the first gain profile with other gain profiles produced from another source of light.
72. The method of claim 71 , wherein:
said suppressing step includes adjusting a power output of at least one of said first pump light, said second pump light, and said another source of light.
73. The method of claim 72 , further comprising a step of:
compensating for optical fiber loss wavelength dependency of pump lights having a wavelength less than the second pump light.
74. The method of claim 62 , further comprising a step of:
compensating for Raman effect between pump lights.
75. A Raman amplifier, comprising:
an optical fiber configured to have a wavelength division multiplex, WDM, optical signal, with a signal bandwidth of at least 20 nm, propagate therethrough
a pump configured to provide pump light to the optical fiber; and
an optical coupler configured to couple the pump light into the optical fiber, wherein the pump includes
a first light source configured to produce light so as to create a corresponding first gain profile having a peak gain at a first wavelength, and
a second light source configured to produce light so as to create a corresponding second gain profile having a peak gain at a second wavelength, wherein
a composite gain profile created from a combination of the first gain profile and the second gain profile has an amplification bandwidth that is at least as great as the 20 nm signal bandwidth, and overlaps said signal bandwidth so as to provide Raman gain to said WDM optical signal,
said second wavelength being at a longer wavelength than the first wavelength, and
said optical fiber to which said pump light is provided is not an Erbium doped fiber of an EDFA.
76. The Raman amplifier of claim 75 , wherein:
the peak gain of the second gain profile being greater than the peak gain of the first gain profile.
77. The Raman amplifier of claim 75 , wherein:
the first light source includes at least one laser configured to produce light at a first pump light wavelength; and
the second light source includes a second laser configured to produce light at only a second pump light wavelength.
78. The Raman amplifier of claim 75 , further comprising:
a controller configured to set a power output of light from said first light source prior to being coupled into the optical fiber to a different level than light from the second light source so as to flatten the composite gain profile.
79. The Raman amplifier of claim 77 , wherein:
said first light source includes at least three lasers configured to respectively produce light at the first pump light wavelength, a third pump light wavelength and a fourth pump light wavelength, which are multiplexed together so as to produce a combined gain profile that has less unevenness than if the first gain profile was produced from pump light having only one wavelength.
80. The Raman amplifier of claim 79 , wherein:
a largest interval between adjacent wavelengths of the first, third and fourth pump light wavelengths being less than a closest wavelength between the second pump light wavelength and any of the first, third and fourth pump light wavelengths.
81. The Raman amplifier of claim 76 , wherein:
the at least one laser being a semiconductor laser.
82. The Raman amplifier of claim 81 , wherein:
said semiconductor laser being a Fabry-Perot laser.
83. The Raman amplifier of claim 82 , further comprising:
an external resonator coupled to an output of the Fabry-Perot laser.
84. The Raman amplifier of claim 81 , wherein:
said semiconductor laser being at least one of a DFB laser, a DBR laser and a MOPA.
85. The Raman amplifier of claim 79 , wherein:
a total gain of said combined gain profile being greater than that of the second gain profile.
86. The Raman amplifier of claim 79 , wherein:
a total pump power of all lasers producing pump light at shorter wavelengths than the second wavelength being greater than a pump power of the second laser.
87. The Raman amplifier of claim 75 , further comprising:
means for suppressing an unevenness in the composite gain profile.
88. The Raman amplifier of claim 87 , wherein:
said means for suppressing includes combining the first gain profile with other gain profiles produced by another source of light.
89. The Raman amplifier of claim 88 , wherein:
said means for suppressing includes means for adjusting a power output of at least one of said first light source, said second light source, and said an her source of light.
90. The Raman amplifier of claim 88 , wherein:
said means for suppressing includes setting the other gain profiles to have a longest wavelength that is closer to one of the wavelengths of the other gain profiles than the second wavelength.
91. The Raman amplifier of claim 75 , further comprising:
means for compensating for optical fiber loss wavelength dependency of the lights from the first light source and the second source of light.
92. The Raman amplifier of claim 75 , further comprising:
means for compensating for Raman effect between lights from the first light source and the second light source.
93. A Raman amplifier comprising:
an optical fiber configured to have a wavelength division multiplex, WDM, optical signal, with a signal bandwidth of at least 20 nm, propagate therethrough;
means for providing pump light to the optical fiber; and
means for coupling the pump light into the optical fiber, wherein
the means for providing light includes
a first means for producing light so as to create a corresponding first gain profile having a peak gain at a first wavelength, and
a second means for producing light so as to create a corresponding second gain profile having a peak gain at a second wavelength, wherein
a composite gain profile created from a combination of the first gain profile and the second gain profile has an amplification bandwidth that is at least as great as the 20 nm signal bandwidth, and overlaps said signal bandwidth so as to provide Raman gain to said WDM optical signal,
said second wavelength being at a longer wavelength than the first wavelength, and
said optical fiber to which said pump light is provided is not an Erbium doped fiber of an EDFA.
94. The Raman amplifier of claim 93 , wherein:
the peak gain of the second gain profile being greater than the peak gain of the first gain profile.
95. The Raman amplifier of claim 93 , wherein:
the first means for producing light includes a first laser that produces light at a predetermined wavelength, and
the second means for producing light includes a second light that produces light at another predetermined wavelength.
96. The Raman amplifier of claim 93 , wherein:
said means for providing light includes means for setting a power output of said first means for producing light to a different level than that for the second means for producing light so as to flatten the composite gain profile.
97. The Raman amplifier of claim 93 , wherein said means for providing light includes:
means for supplementing the first gain profile with other gain profiles to provide a combined gain profile that has less unevenness than if produced from a light source having only one wavelength.
98. The Raman amplifier of claim 93 , wherein:
said means for providing light includes means for stabilizing the light from the first means for producing light and the light from the second means for producing light.
99. The Raman amplifier of claim 97 , wherein:
said means for supplementing provides said combined gain profile with a greater total gain than that of the second gain profile.
100. The Raman amplifier of claim 97 , wherein:
a total pump power of light from said first means for producing light prior to being coupled into the optical fiber being set to a different level than light from the second means for producing light.
101. The Raman amplifier of claim 93 , further comprising:
means for suppressing an unevenness in the composite gain profile.
102. The Raman amplifier of claim 100 , wherein:
said means for suppressing includes combining the first gain profile with other gain profiles produced from another source of light.
103. The Raman amplifier of claim 102 , wherein:
said means for suppressing includes means for adjusting a power output of at least one of said first means for producing light, said second means for producing light, and said another source of light.
104. The Raman amplifier of claim 102 , wherein:
said means for suppressing includes means for setting the other gain profiles to have a longest wavelength that is closer to one of the wavelengths of the other gain profiles than the second wavelength.
105. The Raman amplifier of claim 93 , further comprising:
means for compensating for optical fiber loss wavelength dependency of the lights from the first light source, and the second light source.
106. The Raman amplifier of claim 93 , further comprising:
means for compensating for Raman effect between lights from the first means for producing light, the second means for producing light and the another source of light.
107. A Raman amplifier, comprising:
an optical fiber configured to have a wavelength division multiplex, WDM, optical signal, with a signal bandwidth of at least 20 nm, propagate therethrough
a pump configured to provide pump light to the optical fiber; and
an optical coupler configured to couple the pump light into the optical fiber, wherein the pump includes
a first light source configured to produce light at a first predetermined power level at an output of the first light source so as to create a corresponding first gain profile in said optical fiber having a peak gain at a first wavelength, and
a second light source configured to produce light at a second predetermined power level at an output of said second light source so as to create a corresponding second gain profile in said optical fiber having a peak gain at a second wavelength, wherein
a composite gain profile created from a combination of the first gain profile and the second gain profile has an amplification bandwidth that is at least as great as the 20 nm signal bandwidth, and overlaps said signal bandwidth so as to provide Raman gain to said WDM optical signal,
said second wavelength being longer than the first wavelength, and
said optical fiber to which said pump light is provided is not an Erbium doped fiber of an EDFA.
108. The Raman amplifier of claim 107 , further comprising:
a controller configured to set the second predetermined power level greater than the first predetermined power level so as to flatten the composite gain profile.
109. The Raman amplifier of claim 108 , wherein:
the first light source includes at least one laser configured to produce light at a first pump light wavelength; and
the second light source is configured to produce light at only a second pump light wavelength.
110. The Raman amplifier of claim 107 , wherein:
the first light source includes at least three lasers configured to produce light at the first pump light wavelength, a third pump light wavelength and a fourth pump light wavelength at first, third and fourth power levels respectively, that are multiplexed together so as to produce a combined gain profile that has less unevenness than if the first gain profile was produced from pump light having only one wavelength.
111. The Raman amplifier of claim 110 , wherein:
a largest interval between adjacent wavelengths of the first, third and fourth pump light wavelengths being less than a closest wavelength between the second wavelength and any of the first, third and fourth pump light wavelengths.
112. The Raman amplifier of claim 110 , wherein:
the at least three lasers each being a semiconductor laser.
113. The Raman amplifier of claim 112 , wherein:
each semiconductor laser being a Fabry-Perot laser.
114. The Raman amplifier of claim 113 , further comprising:
an external resonator coupled to an output of the Fabry-Perot laser.
115. The Raman amplifier of claim 112 , wherein:
said semiconductor laser being at least one of a DEB laser, a DBR laser and a MOPA.
116. The Raman amplifier of claim 110 , wherein:
a total pump power of all lasers producing pump light at a shorter wavelength than the second wavelength being greater than a pump power of th second light source.
117. The Raman amplifier of claim 104 , further comprising:
means for suppressing an unevenness in the composite gain profile.
118. The Raman amplifier of claim 117 , wherein:
said means for suppressing includes combining the first gain profile with other gain profiles produced from another source of light.
119. The Raman amplifier of claim 118 , wherein:
said means for suppressing includes means for adjusting a power output of at least one of said first light source, said second light source, and said another source of light.
120. The Raman amplifier of claim 118 , wherein:
said means for suppressing includes setting the other gain profiles to be closer in wavelength to one another than to the second wavelength.
121. The Raman amplifier of claim 104 further comprising:
means for compensating for optical fiber loss wavelength dependency of the lights from the first light source and the second light source.
122. The Raman amplifier of claim 107 , further comprising:
means for compensating for Raman effect between pump lights.Cited by (0)
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